ASLO (Antistreptolysin O)

What is the Antistreptolysin O (ASO) test?

The ASO test measures antibodies produced in response to streptococcal infection, such as strep throat or scarlet fever. It helps diagnose post-streptococcal complications like rheumatic fever or glomerulonephritis.


Who should get this test?

It is recommended for individuals with:

Joint pain, fever, or heart inflammation
Suspected post-streptococcal diseases
History of untreated strep infections



How is the test performed?

A blood sample is analyzed using nephelometry or turbidimetry to quantify ASO antibodies.


What do the results indicate?


High ASO titers: Suggest a recent streptococcal infection.
Normal ASO titers: Rule out recent streptococcal infection.



Can this test confirm an active infection?

No, it indicates past exposure to Streptococcus, not an active infection.